Valve assembly for a fuel gas tank, fuel gas tank, fuel gas tank system and use of a throttle element

Abstract

The invention relates to a valve assembly (1) for a fuel gas tank (2), comprising a valve block (3) in which a refuelling path (4) having an integrated non-return valve (5) is formed, wherein the non-return valve (5) comprises an axially movable valve element (6) and a closing spring (7), the spring force of which acts on the valve element (6) in the direction of a valve seat (8), and wherein a throttle element (9) is integrated in the refuelling path (4) downstream of the axially movable valve element (6) in the refuelling direction. According to the invention, the throttle element (9) is inserted into the valve block (3) or into a housing (10) of the non-return valve (5) connected to the valve block (3), the throttle element being detachably connected to the valve block (3) or the housing (10) and therefore being removable. The invention further relates to a fuel gas tank (2), to a fuel gas tank system (22), and to a use of a throttle element (9) in a valve assembly (1) for a fuel gas tank (2).

Description

[0001] Description as well as a throttle element

[0002] The invention relates to a valve assembly for a fuel gas tank. The fuel gas can, in particular, be hydrogen or natural gas, which is stored under pressure in the fuel gas tank. Furthermore, the invention relates to a fuel gas tank with a valve assembly according to the invention and to a fuel gas tank system. Furthermore, a use for a throttle element in a valve assembly is proposed.

[0003] The preferred field of application of the invention is fuel cell and / or gas vehicles that are powered by a fuel gas.

[0004] State of the art

[0005] Hydrogen produced in a climate-neutral manner is becoming increasingly important as an environmentally friendly energy source, for example as a power source for fuel cell systems or combustion engines, but also for stationary applications. High-pressure gas tanks with pressures of up to 700 bar are used to store hydrogen. Tank valves are usually screwed onto these tanks, which control both the filling and withdrawal of hydrogen. For this purpose, a bore is formed within the tank valve that is divided into two paths: a filling path through which the hydrogen enters the gas tank during a refueling process, and a withdrawal path through which hydrogen flows when hydrogen is withdrawn from the gas tank and fed to the consuming system. The two paths are interconnected within the valve.To prevent uncontrolled hydrogen leakage via the refueling path when the withdrawal path is blocked or during withdrawal, the refueling path is locked with a check valve. This typically comprises an axially movable valve element and a closing spring, the spring force of which urges the valve element toward a valve seat. The check valve opens when the pneumatic pressure conditions acting on the valve element produce a force that opposes the spring force of the closing spring and is at least equal to the spring force.

[0006] In mobile applications, fuel gas tank systems are usually installed which comprise several fuel gas tanks of different sizes in order to make optimal use of the available installation space. Each fuel gas tank is equipped with a tank valve. The goal when refueling such a fuel gas tank system is to fill the several fuel gas tanks of different sizes as quickly and evenly as possible. Therefore, the technically maximum possible dethrottling of the refueling paths of the several tank valves is initially based on the largest fuel gas tank in each case, because this requires the longest filling time. However, a correspondingly maximum dethrottling of the smaller fuel gas tanks results in them being filled more quickly and a significant increase in temperature due to gas compression.To prevent this, throttle elements are integrated into the refueling paths of the smaller fuel gas tanks, reducing the gas mass flow compared to the largest fuel gas tank. Typical required total pressure losses, which must be achieved by the throttle element, are in the order of magnitude of a maximum of 150 bar. The throttle cross-section must be designed so that the greatest pressure drop in the entire refueling path from the high-pressure connection to the fuel gas tank occurs at the throttle point. Due to the variety of tank sizes, a correspondingly large number of customized throttle variants can be expected. However, this increases the average total manufacturing costs.

[0007] The present invention is concerned with the task of demonstrating application-flexible and thus more cost-effective constructive design solutions.

[0008] To achieve this objective, the valve assembly having the features of claim 1 is proposed. Advantageous developments of the invention are set forth in the subclaims. Furthermore, a fuel gas tank having a valve assembly according to the invention and a fuel gas tank system are proposed. Furthermore, the use of a throttle element in a valve assembly is proposed. Disclosure of the Invention

[0009] The valve assembly proposed for a fuel gas tank comprises a valve block in which a refueling path with an integrated check valve is formed. The check valve comprises an axially movable valve element and a closing spring, the spring force of which acts on the valve element in the direction of a valve seat. A throttle element is integrated into the refueling path downstream of the axially movable valve element in the refueling direction. According to the invention, the throttle element is inserted into the valve block or into a check valve housing connected to the valve block and is detachably connected to the valve block or the housing, so that it can be removed.

[0010] The proposed valve assembly can either

[0011] (a) simply by removing the throttle element or

[0012] (b) be adapted to the size of a fuel gas tank within a fuel gas tank system comprising several fuel gas tanks of different sizes by removing the throttle element and inserting a throttle element with a different throttle cross-section. Within this fuel gas tank system, the same valve assembly can therefore be connected to each of the different-sized fuel gas tanks. To adapt the valve assembly to the respective fuel gas tank, simply remove the throttle element and, if necessary, replace it with a different throttle element. The valve assembly itself does not need to be disassembled or modified.

[0013] If the valve assembly is to be connected to the largest fuel gas tank in the fuel gas tank system, a throttle element is generally not required in the refueling path, as maximum dethrottlement is desired here. In this case, only the installed throttle element needs to be removed.

[0014] The positioning of the throttle element downstream of the check valve's valve element is advantageous. This is because the throttle element can be positioned so that it remains easily accessible from the outside. For example, the throttle element can be located in the outlet area of ​​the check valve.

[0015] The downstream position of the throttle element also results in further advantages, particularly with regard to function and structural-mechanical side effects, for example with regard to fluid-mechanical forces due to the sometimes high total pressure losses on the throttle element itself and its installation space. The downstream position also results in advantages in individual part production and assembly. For example, the application-specific adaptation of the throttle element to the size of the respective fuel gas tank can only take place during final assembly of the valve assembly, i.e., at a very late or even the latest possible time during assembly, unless the attachment of a filling lance follows the installation of the throttle element as the last assembly step.

[0016] Following a modular principle, several throttle elements with different throttle cross-sections can be kept in stock. A throttle element tailored to the respective application can then be selected from these and inserted into the valve assembly. In a valve assembly according to the invention, the throttle element can be inserted into the valve block both directly and indirectly via a check valve housing. The housing allows the check valve to be installed as a pre-assembled unit, with or without a throttle element. The version without a housing helps save installation space.

[0017] The detachable connection of the throttle element to the valve block or housing is preferably established via a screw connection, press connection, clamp connection, or indirectly via a removable securing element, such as a retaining ring. Since the throttle element is detachably connected to the valve block or housing, it can be removed without causing damage if necessary. The removed throttle element can then be reused. This conserves resources.

[0018] According to a preferred embodiment of the invention, the throttle element is arranged downstream of the closing spring of the check valve in the refueling direction. In this case, the throttle element can be used to fix the position and / or preload the closing spring. The opening force of the check valve can, in turn, be adjusted via the preload of the closing spring. In a further development of the invention, it is therefore proposed that the closing spring be axially supported on the throttle element.

[0019] Alternatively, it is proposed that the closing spring be axially supported on an annular shoulder of the valve block or the check valve housing. This has the advantage that a throttle element does not necessarily have to be integrated into the refueling path. Furthermore, when replacing the throttle element, the opening force of the check valve does not need to be readjusted. Furthermore, it ensures that the closing spring cannot fall out when the throttle element is removed.

[0020] Advantageously, the throttle element is designed as a rotationally symmetrical body, preferably a cylinder, with a central bore. At least some sections of the bore are designed as a throttle bore. However, other throttle cross-sections are also possible. The rotationally symmetrical design facilitates the insertion and removal of the throttle element. In particular, the angular position of the throttle element is irrelevant.

[0021] Since the preferred application area of ​​a valve assembly according to the invention is fuel gas tanks, a fuel gas tank with a valve assembly according to the invention is further proposed. The valve block of the valve assembly is inserted, in particular screwed, into the fuel gas tank in sections, for example, into a bottle neck of the fuel gas tank.

[0022] Furthermore, a fuel gas tank system is proposed, which comprises at least one fuel gas tank according to the invention or a fuel gas tank with a valve assembly according to the invention. Preferably, the fuel gas tank system has at least two fuel gas tanks of different sizes, of which at least the smaller of the two fuel gas tanks is connected to a valve assembly according to the invention.

[0023] Furthermore, the use of a throttle element for adjusting a gas mass flow in a refueling path of a valve assembly for a fuel gas tank is proposed. The throttle element is selected from a modular system comprising several throttle elements with identical external dimensions but different throttle cross-sections and inserted into the refueling path. The selection of a suitable throttle element allows the gas mass flow to be adjusted to the respective size of the fuel gas tank.

[0024] Preferred embodiments of the invention are explained in more detail below with reference to the accompanying drawings. These show:

[0025] Fig. 1 shows a section of a schematic longitudinal section through a first valve assembly according to the invention in the region of a check valve integrated into a refueling path,

[0026] Fig. 2 shows a section of a schematic longitudinal section through a second valve assembly according to the invention in the region of a check valve integrated into a refueling path,

[0027] Fig. 3 is a schematic longitudinal section through a fuel gas tank with a valve assembly according to the invention,

[0028] Fig. 4 is a highly simplified schematic representation of a fuel gas tank system according to the invention.

[0029] Detailed description of the drawings

[0030] The valve assembly 1 according to the invention for a fuel gas tank 2 shown in Figure 1 is only shown in part, specifically in the area of ​​a check valve 5. The check valve 5 is integrated into a refueling path 4 which is formed in a valve block 3 of the valve assembly 1. The check valve 5 has a housing 10 in which a valve element 6 is received so as to be axially movable. A closing spring 7 is axially supported on an annular shoulder 11 of the housing 10, the spring force of which spring presses the valve element 6 into a valve seat 8. The check valve 5 opens depending on the pressure conditions at the valve element 6. When the check valve 5 is open, it releases the refueling path 4 so that fuel gas flows into the fuel gas tank 2 in the refueling direction (see arrows in Figure 1). The fuel gas tank 2 is not shown in Figure 1.

[0031] A throttle element 9 is inserted, for example screwed or pressed, into the housing 10 of the check valve 5 downstream of the valve element 6 and the closing spring 7 in the refueling direction. The throttle element 9 is therefore detachably connected to the housing 10. This means that the throttle element 9 can be removed if necessary. This is the case, for example, if the valve assembly 1 is to be connected to a fuel gas tank 2 that has a different size, so that the throttle cross-section of the throttle element 9 must be adapted to the size of the fuel gas tank 2. The adaptation can then be carried out by either (a) removing the existing throttle element 9 or (b) replacing the existing throttle element 9 with another throttle element 9 that differs from the first throttle element 9 in its throttle cross-section.In the throttle element 9 shown in Figure 1, the throttle cross-section is defined by a central bore 12, which in this case is designed as a throttle bore.

[0032] Figure 2 shows a further preferred embodiment of a valve assembly 1 according to the invention. The check valve 5 is inserted directly into the valve block 3, i.e., without a housing 10. The closing spring 7 is axially supported not on an annular shoulder, but on the throttle element 9. The spring force of the closing spring 7, and thus the opening force of the check valve 5, can be adjusted by adjusting the screw-in or press-in depth of the throttle element 9. The omission of the housing 10 also helps save installation space.

[0033] Figure 3 shows a valve assembly 1 according to the invention in conjunction with a fuel gas tank 2. The valve block 3 of the valve assembly 1 is inserted, for example screwed, into the fuel gas tank 2 in sections. The check valve 5 integrated into the refueling path 4 thus comes to lie within the fuel gas tank 2. The refueling path 4 ends in a filling lance 13, with the aid of which the fuel gas can be introduced into the fuel gas tank 2 in a targeted manner, so that the heat generated during refueling is distributed as evenly as possible. To detect the temperature, the valve assembly 1 has a temperature sensor 20, which also projects into the fuel gas tank 2. To remove fuel gas from the fuel gas tank 2, a removal path 14 is formed in the valve block 3 of the valve assembly 1, into which a shut-off valve 15 is integrated.Downstream of the shut-off valve 15 in the withdrawal direction is another check valve 16, which is intended to prevent the shut-off valve 16 from opening accidentally during refueling. This is because the withdrawal path 14 and the refueling path 4 are interconnected in the valve block 3. This has the advantage that the valve assembly 1 only needs one high-pressure connection for connection to a high-pressure line 18. To prevent particles from entering the valves of the valve assembly 1 via the high-pressure line 18, several filters 17 are integrated into the valve block 3. Furthermore, additional valves 19 are integrated, which primarily serve safety purposes.

[0034] Figure 4 shows an example of a fuel gas tank system 22 with at least two fuel gas tanks 2 of different sizes. At least the smaller of the two fuel gas tanks 2 has a valve assembly 1 according to the invention with a check valve 5 and a throttle element 9 in the refueling path 4, wherein the throttle element 9 is arranged downstream of the check valve 5 in the refueling direction. The fuel gas tanks 2 are connected in parallel and connected to a system distributor 21. During refueling, fuel gas is taken from a filling station 23 and distributed to the fuel gas tanks 2 via the system distributor 21. In this case, the throttle element 9 arranged downstream of the check valve 5 of the smaller fuel gas tank 2 contributes to the fuel gas tanks 2 being filled quickly and evenly.

Claims

Claims 1. Valve assembly (1) for a fuel gas tank (2), comprising a valve block (3) in which a refueling path (4) with an integrated check valve (5) is formed, wherein the check valve (5) comprises an axially movable valve element (6) and a closing spring (7), the spring force of which acts on the valve element (6) in the direction of a valve seat (8), and wherein a throttle element (9) is integrated into the refueling path (4) downstream of the axially movable valve element (6) in the refueling direction, characterized in that the throttle element (9) is inserted into the valve block (3) or into a housing (10) of the check valve (5) connected to the valve block (3) and is detachably connected to the valve block (3) or the housing (10) so that it can be removed.

2. Valve assembly (1) according to claim 1, characterized in that the detachable connection of the throttle element (9) to the valve block (3) or the housing (10) is made via a screw connection, press connection, clamp connection or indirectly via a removable securing element, for example a retaining ring 3. Valve assembly (1) according to claim 1 or 2, characterized in that the throttle element (9) is arranged downstream of the closing spring (7) in the refueling direction.

4. Valve assembly (1) according to one of the preceding claims, characterized in that the closing spring (7) is axially supported on the throttle element (9).

5. Valve assembly (1) according to one of claims 1 to 3, characterized in that the closing spring (7) is axially supported on an annular shoulder (11) of the valve block (3) or the housing (10).

6. Valve assembly (1) according to one of the preceding claims, characterized in that the throttle element (9) is designed as a rotationally symmetrical body, preferably as a cylinder, with a central bore (12).

7. Fuel gas tank (2) with a valve assembly (1) according to one of the preceding claims, wherein preferably the valve block (3) of the valve assembly (1) is inserted, in particular screwed, in sections into the fuel gas tank (2), for example into a bottle neck of the fuel gas tank (2).

8. Fuel gas tank system (22) with at least one fuel gas tank (2) according to claim 7.

9. Use of a throttle element (9) for adjusting a gas mass flow in a refueling path (4) of a valve assembly (1) for a fuel gas tank (2), wherein the throttle element (9) is selected from a modular system comprising several throttle elements (9) with the same external dimensions but different throttle cross-sections and is inserted into the refueling path (4).

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